Yah, like turning up volume full blast, only right before/at overload. It'll always playback at correct level, only at the moment it overloads.
End of session has everything at that point (automation/3rd party plug etc), so it's hard to tell. I'll try running some more test again... But far as my experience goes, this tends to happen when there're lots of latency going on. Not something new, just finally getting onto my nerves with mixes lately..